Late-stage Alzheimer's drug targets two key culprits

Researchers involved in the ambitious development program for bapineuzumab say that the amyloid-targeting drug also attacks a second key culprit implicated in the mind-wasting disease. Patients enrolled in two mid-stage clinical trials for bapineuzumab demonstrated its effect in lowering the level of tau, a toxic protein that spurs the development of brain tangles.

"If you lower tau levels, it's logical to assume that this will have an effect on cognition," Dr. Kaj Blennow of the University of Gothenburg said at the Alzheimer's Association scientific meeting. But even though it's logical, Blennow also is quick to note that scientists still don't know for a fact what role tau plays in Alzheimer's. And even though amyloid has long been suspected as a key trigger, there's also no conclusive evidence that lowering the level of that toxic protein in the brain can alleviate the disease. Nevertheless, the scientists say they're encouraged going into late-stage testing.

"When you take together all the data we have from Phase II, I think it's encouraging and it supported going forward into Phase III," says J&J's Dr. Eric Yuen. Bapineuzumab is being developed by a team of scientists backed by Pfizer, Elan and J&J. A year ago J&J invested $1 billion into Elan in exchange for a minority stake in the pharma company and a big role in its Alzheimer's work. The bapineuzumab program played a central role in that deal.